In the future, more heat-recovery ventilation devices will be installed in new apartment buildings, which will lead to greater comfort, because they ensure automatic required air exchange and heat recovery which distinctly raises the temperature of the fresh air. Moisture in the living quarters is continually removed, which prevents damage to the buildings from moisture. Utilizing the exhaust air to preheat the fresh air can lower heat requirements and in this way save energy. For this reason, these systems are granted a bonus status in present heat protection regulations and with all probability new energy saving regulations will do so as well.
If such a ventilation system is combined with a ground heat exchanger to preheat fresh air, the temperature of the exhaust air is of a magnitude, even after discharging heat to the fresh air, which permits energy-efficient use by a heat pump. The heat pump can discharge recovered heat into the fresh air in conjunction with the converted-into-heat drive energy when heat is required and otherwise stand at disposal for heating drinking water.
In a low energy house, it can cover a substantial part of the heat requirements. Outside the core heating period, the exhaust air heat pump can cover warm water preparation fully. In combination with a thermal solar system, it increases energy efficiency.
In a passive house, the described combination of devices can cover all heat requirements entirely. Elimination of the still necessary auxiliary heating system in a low-energy house reduces investment in building technology.
The heating requirements for heating domestic-use water in a low-energy house may amount from 30% to 50% of the overall heating requirement and even dominate in a passive house. Heating the water by means of the heat pump requires higher temperatures than for heating fresh air, thereby generally lowering the efficiency of the heat pump (performance number).
Moreover, for better summer comfort, frequent cooling of the living quarters is desirable. Increasing sales of usually less efficient room-cooling devices is evidence of this general demand.
There are various approaches to realize utilizing heat at varying temperatures. Fundamentally, two liquefiers are connected in such a manner that a coolant flows through them in series. However, if only one of the two types of heating requirements is needed (heating the air or heating the domestic-use water), either one liquefier is circumvented by a bypass or heat is discharged, although undesired, at a location where it is not needed. If this heat loss is to be prevented and if it is also required that the heat pump be operable in a cooling circuit while, if possible, heating domestic-use water as well, very complicated and therefore expensive circuits that are susceptible to malfunction have hitherto been realized.
The present invention provides a ventilation arrangement for buildings in such a manner that the aforedescribed, partly dominating heating requirements are met with greater performance numbers and greater warm water comfort, while permitting easy combination with a varying buffer storage for thermal solar systems. In addition to this, the invention allows cooling living quarters for greater summer comfort. Finally, the ventilation arrangement provides inexpensive manufacturing and operating as well as being reliable.
The solution thereto is a ventilation arrangement for buildings with heat removal from an exhaust-air flow (LAb(off)) discharged from the building and/or from a fresh-air flow (Lzu(on)) supplied to the building, the arrangement having a heat pump which has a coolant/water heat exchanger (WW) with a mass flow controlled by a water system and having a coolant/air heat exchanger (LWZU, LWAb) serving the fresh-air flow (Lzu) and the exhaust-air flow (LAb) the coolant/air heat exchanger (LWzu, LWAb) being connectable in series to the coolant/water heat exchanger (WW).